1. Field of the Invention
The present invention relates to holographic lenses for eyesight correction and to a method for creating such lenses.
2. Description of the Prior Art
For the purposes of this application, holography can generally be defined as a lenseless photographic method that uses laser light to produce 3-dimensional images by splitting the laser beam into two beams and recording on a photographic surface the minute interference patterns made by the reference light waves which may be reflected from a mirror and the waves modulated when simultaneously reflected from the object. The virtual image can be reconstructed by shining laser light, white light, etc. through the developed film.
A method of recording and reproducing wave fronts was proposed by D. Gabor in the publication "NATURE" 161 777 (1948) for use in microscopy.
The subsequent development of laser technology resulted in a whole new branch of optic science being formed which was named holography. Holography is based on the recording of the mutual interference of two coherent optical waves originating from the same laser source on a photosensitive material. The interference requires two beams: the reference beam which is usually a plane parallel wave of constant amplitude and phase, and the object beam which is light scattered from the object to be recorded and therefore carries amplitude and phase information related to it. This mutual interference of a coherent reference beam and a coherent object beam results in not only the recording of the average intensity (as in ordinary photography) but also the phase of the waves. Thus the hologram holds all the information relative to the object beam and can reproduce it as well.
In prior art processes the hologram recording is processed by chemical means as in ordinary photography. The process material is illuminated by the reference beam used during the recording, its diffraction reproduces exactly the recorded object beam.
Other prior art publications which are relevant to the present invention include "HOLOGRAPHIE" by M. Francon, published by Masson & Cie (1969); "OPTICAL INFORMATION PROCESSING AND HOLOGRAPHY" by W. T. Cathey, published by J. Wiley (1974); and "OPTICS" by M. B. Klein, published by J. Wiley (1970).